Animal invaders threaten protected areas worldwide

Area of Science:

• Ecology
• Conservation Biology
• Invasive Species Management

Background:

• Protected areas are crucial for biodiversity conservation.
• Alien species invasions represent a significant and escalating threat to global biodiversity.
• Understanding the vulnerability of protected areas to alien species is essential for effective conservation strategies.

Purpose of the Study:

• To assess the global extent of alien animal establishment within protected areas.
• To evaluate the proximity of alien species populations to protected area boundaries.
• To identify factors influencing alien species richness within protected areas.

Main Methods:

• Analyzed establishment data for 894 terrestrial alien animal species across 199,957 protected areas worldwide.
• Examined 11 major taxonomic groups, including vertebrates and invertebrates.
• Correlated alien species richness with protected area characteristics (IUCN category, size, human footprint, designation date).

Main Results:

• Less than 10% of protected areas contain established alien animal populations.
• Established alien populations exist within 10-100 km of 89%-99% of protected areas.
• Over 95% of protected areas are environmentally suitable for alien species establishment.
• Higher alien richness was found in larger, IUCN category-II protected areas with greater human footprint and more recent designation.

Conclusions:

• Protected areas offer significant but not absolute protection against biological invasions.
• Alien species pose a substantial and growing threat to the integrity of protected areas.
• Future conservation efforts must address the increasing risk of alien species incursions.